Air conveyors are known in the art and use directed air flows to move articles from one location to another. The air flows can support and move the articles. Examples of air conveyors are provided in U.S. Pat. Nos. 3,684,327, 4,500,229, 4,369,005 and 3,734,567.
These conveyors commonly include a longitudinal plenum containing pressurized air and having an upper panel provided with a pattern of air nozzles. Articles riding the conveyor actually ride on the air cushion created by air escaping the nozzles under pressure. The upper panel is commonly provided with side walls so as to form a U-shaped channel wherein articles are conveyed.
A number of air conveyor variations are known in the art. For example, the size, placement and orientation of nozzles can vary. To urge articles in a predetermined direction, an array of nozzles have an oblique-axis orientation with respect to the planar surface defined by the conveyor upper panel. When only lift is required, nozzles are oriented at right angle with respect to the upper panel. Also, the size and shape of the nozzles may vary. The best control over the articles being conveyed is usually obtained when the nozzles are numerous, quite small in diameter and the pressure inside the plenum is high. This will result in good conveying performance obtained by precise, high velocity air jets impacting and directing the articles being conveyed.
In manufacturing air conveyor panels, it is known to use metallic, polymeric or composite materials. However, in many materials, it is not technically possible to create very small nozzles by conventional drilling or punching techniques. This is a major drawback, because the use of larger diameter nozzles compels air conveyor designers to produce high volume, low pressure conveyors. As a further drawback, when machining oblique-axis nozzles, it is common to use a two step method including a first step of drilling or punching a right angle bore to a predetermined depth in the conveyor upper panel followed by a second step of drilling or punching an oblique-axis hole starting at the depth of the right angle bore.
To overcome some of these drawbacks of the prior art, it is known from U.S. Pat. No. 5,456,556, to prepare an upper conveyor panel provided with large nozzles adapted to receive nozzle inserts which are friction fitted into each large nozzle. The nozzle inserts are usually molded with small diameter nozzles of any given orientation. Although such arrangement is meritorious, each nozzle insert is installed by hand. The injection molding of nozzle inserts also adds expense to the overall cost of manufacture. Thus, this technique has so far received limited favour in a mass-production setting.
It is also known to use lasers for drilling or machining workpieces for example when making semi conductors (see for example U.S. Pat. No. 5,580,446). However, the prior art does not teach the use of laser to manufacture air conveyor panels.
Consequently, there remains a need for an improved, low cost, high production method of manufacturing air conveyor panels which overcome the drawbacks of the prior art.